The gospel’s favorite tense is future. Everything in it calls believers to stand on tiptoe and to await, eagerly, confidently, and with joy-filled longing, the day when their Lord returns to earth. Then his kingdom will appear in full splendor. Then he shall take them home. Then they “shall be with the Lord forever” (1 Thess. 4:18).

How can God’s children know—for sure—that the Lord will make good on his promise to return and “to make all things new” (Rev. 21:5)? Their confidence rests upon the Spirit of Jesus Christ, whom the Lord has sent to dwell within his followers. The Spirit serves as a “seal,” a pledge that one day soon they will receive their final inheritance (cf. Eph. 1:14). The word for “seal” which St. Paul uses means “promise,” a sort of engagement-ring pledge from the Savior to his beloved bride, the church.

The church cannot be the church without the Spirit’s guarantee. Via the Spirit, the company of Christians already “lives into the future,” so to speak. They receive in the here and now a foretaste of what is to come. St. Paul declares boldly: “If anyone is in Christ, behold … a new creation!” (2 Cor. 5:17).

Present tense. Right now.

Paul’s breathtaking claim elicited a no less breathtaking—and prophetic—claim from contemporary Biblical scholar N. T. Wright: “Those who follow Jesus, those who find themselves believing that he is the world’s true Lord, that he rose from the dead—these people are given the Spirit as a foretaste of what that new world will be like. If anyone is ‘in the Messiah,’ what they have and are is—new creation.… The Spirit is the strange, personal presence of the living God himself, leading, guiding, warning, rebuking, grieving over our failings and celebrating our small steps toward the true inheritance.” A time-honored Christian confession of faith, the sixteenth-century Heidelberg Catechism, declares the same truth: “By the Spirit’s power we make the goal of our lives not earthly things, but the things above where Christ is, sitting at God’s right hand” (Q&A 49).

Christian hope saves (cf. Rom. 8:23). It serves as a mask, protecting God’s children from the noxious, smothering fumes of aimlessness, futility, and despair which hang heavy upon contemporary culture. Hope empowers them to endure with steady, sturdy patience (cf. Rom. 8:25) all of life’s circumstances, come what may.

It is the Spirit who helps saints keep Christian hope alive. Except for the Guarantor’s presence, followers of Jesus would sink into despair. They would face (their) death with dread terror. With the Guarantor present, however, they can keep hope alive and live well during their days here upon earth. With the Guarantor present, they can learn to die well, and await with confidence the day when they shall stand before the face of the Judge who has become their Savior.

Christian hope requires continual refreshing, regular cultivating. Where better to do this than in the assembly of the saints, who gather on Sunday for worship? In the sanctuary of God’s presence the faithful gather to thank God for the gift of the Guarantor Spirit. There they imagine—they sing!—their dream of what is to come:

He by his name has sworn, on this we shall depend, And as on eagles’ wings upborne to heaven ascend. There we shall see his face, his power we shall adore And sing the wonders of his grace forevermore.

The goodly land I see, with peace and plenty blest, A land of sacred liberty and endless rest. There milk and honey flow, and oil and wine abound; The tree of life forever grows with mercy crowned.

There they gather to plead:

Come, thou long-expected Jesus, born to set thy people free; From our fears and sins release us, let us find our rest in thee.

Though it happened more than three decades ago—on August 9, 1977, to be exact—I remember the event as though it happened yesterday. My heart heavily homesick for my family from whom I had been separated the entire summer, I cut short my doctoral research in Geneva and headed home. At Chicago’s O’Hare airport I phoned Marcia to arrange for her to meet me at the Grand Rapids airport. While we were talking with each other, our four-year-old Dan tugged at Marcia and pleaded, “I want to talk to Daddy. I want to talk.” Marcia handed him the phone. His only words to me— a sigh, really: “Daddy, when am I going to be where you are?”

I know of no finer description of heaven than my son’s longing plea. No one knows the fine-print details of what heaven will be like—certainly not I. But of this truth believers can be certain: We shall be with the Lord forever. The Spirit serves as Pledge and Guarantor of it. It’s enough to know.

And as for the rest, those further details about heaven that Scripture doesn’t reveal, we do well to heed the advice of John Bunyan. To a pestering, too-curious parishioner who wanted to know more—and yet more—information about the life to come than Bunyan could provide, he replied: “Believe the gospel. Live a holy life pleasing to God. And go and see for yourself.